The depth of field is going to be a feature exclusive to the iPhone 7 Plus, two lenses are required to achieve the effect.
And yes the camera is going to be that much better than that of the IPhone 7 4.7 inch Model and previous iPhone models.
And the Optical Zoom feature is important because if you try to take an up close photo of something small such as a wrist watch for example, you can only get so close to the Watch with the iPhone camera that the focus no longer works so you need to move away from the object, in other words, macro photography will benefit from the optical zoom as well
I mentioned the advantages of the Plus model above, 3Gb of ram Vs 2gm is a big deal as well and a very welcome addition
Thanks for the explanation! The camera was my biggest concern, though the extra gb of RAM is also a nice bonus.